Fuel-feeding device for internal-combustion engines



Nov. 23 1926. 1,607,753

R. HILDEBRAND FUEL FEEDING DEVICE FOR INTERNAL COMBUSTION ENGINES FiledNov. 27, 1922 By @GUM m A r TOR/YE vs Patented Nov. 23, 1926.

UNITED STATES PATENT OFFICE.

REINHARD HILDEBRAND, OF WEESTER GROVES, MISSOURI, ASSIGNOR TO FULTONIRON WORKS COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF DELAWARE.

FUEL-FEEDING DEVICE FOR INTERNAL-COMBUSTION ENGINES.

Applicationfiled November 27, 1922. Serial No. 603,616.

5 oil from entering the fuel injection valve or the working cylinder ofan internalcombustion engine, while the fuel pump is being primed.Another object of my invention is toequalize the load betweenythecylinders of an internal combustion engine. A further object is to avoidthe dripping of the fuel at the intake nozzles of the internalcombustion engines.

The ordinary priming devices for internal combustion engines do notpositively prevent fuel oil from entering the fuel injection valves, orthe working cylinders, while the fuel pumps are being primed. Thisfrequently results inaccidents when the engine is started because thefirst opening of the fuel injection valve admits into the workingcylinder an excess of fuel oil, which was previously primed into ,thefuel injection valve. My invention furnishes a means by improper primingis eliminated.

Fig. 1 is a diagrammatical view showing the general arrangement of aworking cylinder, a fuel pump and the priming device.

Fig. 2 shows the valve of my priming device, the parts of said valvebeing'shown in the positions they will assume while the fuel pump isbeing primed.

Fig. 3 shows-a modified form of the valve of my priming device as itwill appear while the engine is in operation.-

Fig. 4c shows my primin device applied to an engine of the so-callesolid injection type.

The letter a indicates a working cylinder of an internal combustionengine; I) a fuel injection valve; 0 the needle of the fueljnjectionvalve in lifted position; d indicates a fuel pump with plunger 6, asuction valve 7 and discharge valve 9'. The fuel pump, while the engineis in operation, sucks the fuel oil by means of pipe h from receptacle iand discharges the fuel oil through pipe 70, priming valve m and pipe ninto the fuel 59 in'ection valve 6. High pressure air.1s adinto the fuelinjection valve 6., into the working cylinder a. I

When the engine is in operation the valve stem 0 of the priming valve mis screwed down on its seat as shown in Fig. 3. Thus the fuel oil,entering the priming valve m through pipe 70, will flow through passages2), g, and '2", through passage t and pipe n into the fuel injectionvalve" 6, whence it is blown into the working cylinder (1.

Before the engine is started and before the fuel pump is primed, theValve stem 0 of the priming valve m is :rewed ou wardly until its collar'2; comes in contact with the stop to, as shown in Fig. 2. In thisposition, the piston X being connected to the valve stem 0 by means ofrod ;2 will close the passage p. If now the priming pump 2 (Fig. 1) isoperated, fuel oil will be sucked through pipe 1 and discharged throughpipe 2 into the fuel pump 03 from which it passes discharge valve g, andthrough pipe is, open passage 3 (Fig. 2), passage i, pipe 5, cock 6 (F1g. 1) funnel 7, and pipe 8, leading back into the receptacle 2'. Thefuel oil thus primed through the fuel pump d will displace any air whichmay be in the fuel pump or its discharge pipe. After the fuel pump andits discharge pipe is primed, the valve stem 0 is screwed down on itsseat as shown in Fig. 3 and the engine is then ready to be started.

It will be understood that the described means of priming prevents anyfuel oil from entering the fuel injection valve or the workingcylinder'while the fuel pump is being primed, because the piston 02(Fig. 2) shuts ed the passage p to the fuel injection valve during thepriming period. Therefore, when the engine is started, i. e., when theneedle 0 of the fuel injection valve b-begins to lift, no excessivepressure (explosion) inside of the working cylinder can occur, becauseno excess of fuel oil will enter the working cylinder through the fuelinjection valve, as no fuel oil was accumulated therein while primingthe fuel pump. My priming device is therefore a simple and effectivemeans to prevent accidents in starting the engine. The priming valve issubstantially a two-way valve, consisting of the needle 0 (see Figs. 2and 3) and piston 00, both being connected by rod :1 This two- -wayvalve permits the fuel oil flowing through pipe (Figs. 2 and 3) to passeither through pipe a into the fuel injection valve, or through pipe 5into the overflow funnel 7.

In Fig. 3 of the drawing I show a priming valve associated with a checkvalve S for preventing fuel oil from entering the fuel chamber duringthe priming period. However, said valve is not essential and can bedispensed with, as my priming valve furnishes a positive means forpreventing fuel oil from being primed into the fuel injection valve.

Some types of internal combustion engines do not use compressed air toinject the fuel, but pump the fuel oil directly into the workingcylinder eliminating the fuel injection valve 1) shown in Fig. 1. Fig. 4illustrates such a type of engine. There a shows the working cylinder,is indicates the discharge pipe from the fuel pump, m shows my primingvalve and 5' the return flow pipe. The fuel oil coming from the fuel umthrou h )i e la arimin valve m and pipe 72', will pass through passage 9and nozzle 10 directly into the working cylinder. The application of mypriming valve to an engine of this kind will prevent accidentalexplosion in the working cylinder when the engine is started, because itwill prevent the entering of fuel oil into the working cylinder duringthe priming of the fuel pump.

My two-way valve 0, 3 and 00 (Figs. 2 and 3) will also serve for thefollowing purpose: In case the engine has several working cylinders, itis sometimes ditlicult to equalize the load between the severalcylinders. These uneven loads are due to the fact that the fuel oilsupply to the various cylinders is not equal, My two-way valve furnishesa convenient means to equalize the fuel oil delivered to the variouscylinders. This can be accomplished by slightly screwing outwardly thevalve stems 0 associated with those cylinders which receive too muchfuel oil, thus permitting some of the fuel oil to escape throughpassageway 4 and flow back through the return pipe 5. My priming valvealso acts, therefore, as a convenient bleeder valve for equalizing theloads between the several cylinders of the engine.

In' case the engine is of the solid injection type, the compressed airfor injection of the fuel oil into the working cylinder is eliminated.Then my priming valve will perform another function. In a solidinjection engine (Fig. 4) the fuel valve 6 and the check valve 8 aregenerally eliminated, and the fuel oil is forced by the fuel pumpdirectly into the combustion chamber of the engine. Here it is veryimportant that, as soon as the fueloil discharge from the fuel pumpceases, the pressure in the pipe is and n be released as quickly aspossible, to avoid fuel oil dripping from the nozzle 10. This releasingof the pressure in the pipe in and n is conveniently accomplished bykeeping the valve stem 0 of my priming valve adjusted'slightly outwardlyfrom the position shown in Fig. 3, so that a small amount of fuel oilwill bleed back through return pipe 5 or 5. By maintaining the properadjustment while the engine is running, a convenient means is providedto instantly stop the delivery'of fuel when the pump completes itspressure stroke, and this avoids dripping of the fuel at the nozzle 10.Under these conditions, a fine spray of atomized fuel issues from thenozzle during each pressure stroke of the pump, but immediately upon thecompletion of the stroke, the pressure in the engine cylinder forces theexcess fuel backwardly in the nozzle, thereby preventing the delivery ofexcess fuel in the formof'solid drops which would not be effectivelyconsumed. In this case the fuel pump must deliver a slightly greateramount of fuel oil than needed for combustion, be cause a small part ofit is allowed to bleed back through the'priming valve m into the returnpipe 5 or 5.

I claim:

1. An internal combustion engine provided with a combustion chamber, afuel pump having a discharge conductor for the delivery of liquid fuelto said combustion chamber, a priming device arranged to deliver primingliquid to said pump, said discharge conductor being provided with anoutlet for the fluid escaping from said pump when the priming device iseffective, a valve member adapted to close communication between saidpump and combustion chamber to prevent the delivery of priming liquid tosaid chamber, a-valve member adapted to open said outlet to permit freeescape of said fluid, and an operating handle common to both of saidvalve members.

2. -An internal combustion engine provided with a combustion chamberhavin a fuel injector for the admission of liqui fuel, a fuel pump, aconductor whereby the liquid fuel is delivered from said fuel pump tosaid fuel injector, a priming device arranged to discharge primingliquid through said fuel pump and into said conductor, and means forpreventing the delivery of priming liquid to said fuel injector, saidmeans including a manually operated valve arranged in said conductor topositively close communication between said priming device and fuelinjector, and said conductor being provided with an outlet for excesspriming liquid.

An internal combustion engine profuel, a fuel pump provided with adischarge '4. An internal combustion engine pro-.

videdwith a combustion chamber having a fuel injector for the admissionof liquid fuel, a fuel pump provided with a discharge conductor for thedelivery of liquid fuel to said fuel injector, apriming device arrangedto deliver priming. liquid to: said pump, said discharge conductor beingprovided with an.outlet for the fluid escaping from said pump When thepriming device is effective, a valve member adapted to closecommunication between said pump and fuel injector to prevent thedelivery of priming liquid to said chamber, and a valve member adaptedto open said outlet to permit free escape of said fluid.

5. An internal combustion engine provided with a combustion chamberhaving a fuel injector for the admission of liquid fuel, a fuel pumpcomprising a pump chamber provided with intake and discharge valves anda plunger whereby liquid fuel is drawn into and discharged from saidpump chamber, a conductor leading from said discharge valve to said fuelinjector, a valve member arranged 111 said conductor to controlcommunication between said pump chamber and the fuel injector, saidconductor having an outlet between the last mentioned valxe and saiddischarge .valve, apriming pump communicating with said pump chamber toprovide for the delivery of priming liquid into-said conductor andthrough said outlet, and a valve member adapted to close said outlet.

6. An internal combustion engine provided with a combustion chamber, afuel pump having a discharge conductor for the delivery of liquid fuelto said combustion chamber, a priming device arranged to deliver primingliquid to said pump, said discharge conductor being provided with anoutlet for the fluid escaping from said pump when the priming device iseffective, a valve member adapted to close communication between saidpump and combustion chamber to prevent the delivery of priming liquid tosaid chamber, and a valve member adapt-- ed to open said outlet topermit free escape of said fluid, said valve members being operati'velyconnected together and so arranged that one valve member will 00- cupyits closed position While the other is in its open position.

In testimony that I claim the foregoing 65 I hereunto affix mysignature.

REINHARJ) HILDEBRAND.

